Process of making stable zinc hydrosulfite.



UNITED sTATEs PATENT oEEioE.

.vlfiX BAZLEN AND THEODOR WOHLFAHRT, OF LUDWIGSHAFEN-ON-THE-RHINE, GERMANY, ASSIGNORS TO BADISOHE ANILIN & SODA FABRIK, OF LUDWIGSHAFEN-ON-THE-RHINE,

GERMANY, A CORPORATION.

. IROCESS O1 MAKING STABLE ZENC HYDBOSULFI'IE.

Specification 61 Letters Patent.

Patented Aug. 18, 1908.

Application filed October 3,1907. Serial No. 395,791.

0 all whom it may concern:

Be it known that we, MAX BAZLEN and author poured absolute alcohol (which had been 'listilled several times over sodium) onto granulated zinc and then passed m sul- .fur dioxid, While cooling in order to prevent decomposition of the zinc salt formed. The zinc hydrosulfite is thus obtained in the form of long needle-like crystals, and is unstable,

as, even when in closed vessels, it evolves.

sulfur dioxid after a few days, while in the presence of the atmosphere, its reducing power diminishes rapidly and it is therefore (in common with zinc hydrosulfite which has been prepared in aqueous solution) unsuitable for use in manufactures.

We have discovered that by passing a current of sulfur dioxid into a mixture of zinc dust and alcohol at a temperature above 40 centigrad-e (preferably between 60 and 75 centigrade) zinc hydrosulfite is obtained which possesses excellent keeping properties.

in carrying out our invention either absolute, or diluted,- alcohol can be employed. When diluted alcohol is used, it is preferred to use such a concentration that the zinc hydrosulfite formed remains, as far as )ossible, undissolved. The zinc hydrosulhte is obtained, in almost theoretical yield,.and is in the form of large sixsided, transparent leaflets, and, after drying, for instance in Mean, isjol' excellent. stability.

Either ethyl alcohol, or other alcohols, such for instance as methyl-alcohol, amylalcohol, and. glycerin, and' also other liquids sulfite from going into solution, can be employed in carrying out this invention.

The following is an example of how' our invention can be carried into practical ell'eet, but it is not confined to this example. The parts are by weight. Alloiwfour hundred and seventy (470) parts ol sulfur dioxid to react on a mixture of six hundred (600) arts of methylated spirits, two hundred which substantially prevent the zinc hydro and fifty (250) parts oi "water and two hundred and sevent- \"(270) parts olzine dust, at a temperature of from sixtyttitl), to seventvfive (75), degrees eentigrade, while well stirring the mixture. A paste of crystalline zinc lrwlrosullite is thereby obtained Fil-. ter this oil', and wash it with methylated spirits and dry it in cacao at a temperature of from sixty ((50), to seventy degrees centigi'ade,-tl1e zine hydrosuliite being thus obtained in. the condition of dry powder.

Now what we claim is: 1. The process of producing stable solid zinc hydrosuliite by passing, a current of sulfur dioxid into a mixture of zinc (lust and a liquid which substantially prevents the zinc hydrosulfite from going into solution, at a temperature above forty degrees eentigrade.

-2. The process of producing stable solid zinc hydrosulfite'by passing a current of sulfur dioXid into a mixture of zinc dust and alcohol at a temperature above forty degrees eentigradc.

3. The process of proi'lucingstable solid zinc hydrosuliite by passing a current of sulfur dioxid into a mixture of zinc dust and ethyl alcohol at a temperature between sixty and seventy-five degrees Centigrade.

In testimony whereof we have hereunto set our hands in the presence ii-two subscribing witnesses.

MAX BAZIJEN. 'llllGODOli '(llllll nll'li'l.

l vitnesses:-

Ennns'r F. Emumun'r J. ALEU. lrunn. 

